That means that it is no longer hidden to you, because you now know about it.

I've known about it for a long time, so it would not occur to me that you consider it hidden.

If you read the help files (F1)

You will find under Analytics\Graphical Objects

"The object visualization mode for different
timeframes can be changed in the "Visualization" tab. The object will then be
shown only for the selected timeframes. This can be useful when the tool has
different settings for different timeframes. The "Fibo Levels" tab is
specifically used only for Fibonacci tools. The list of the tool levels is given
here in form of a table. The values of the levels can be changed or deleted (the
"Delete" button). A new level can be added by pressing of the "Add" button. At
that, if "(%$)" is entered in the "Description" field, the price value
corresponding with this level will be shown in the chart. The "Defaults" button
resets the initial values. The "Style" field that allows to set up the color,
appearance, and thickness of levels of the object is located in the lower part
of the tab."